Final Report: Batanes Islands Biodiversity Survey
Identifying conservation priorities for terrestrial vertebrate fauna within the Batanes Islands, Northern Philippines
Juan Carlos T. Gonzalez, Leticia E. Afuang and Aurora V. Lacaste
Animal Biology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños, College, Laguna 4031
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Summary
Batanes Province harbors a moderately rich assemblage of terrestrial fauna due to its limited area and remote location in the
Philippines, nearly equidistant to both Palearctic Taiwan and Wallacean Luzon. This isolation produced several endemic reptiles, birds
and mammals allied to species from subtropical Taiwan-Ryukyus or tropical Philippines. This complementary mix of wildlife regarded
Batanes as a distinct transitional biogeographic region (parallel with Babuyan Islands). Due to its unique geology, endemic fauna &
flora, and indigenous Ivatan culture, the entire province was designated as a protected landscape & seascape and UNESCO heritage
site. Past biological expeditions were concentrated around Mt. Iraya, Batan Island that revealed several endemic taxa. Despite being a
priority protected area, little is known about the wildlife of other islands, particularly on smaller uninhabited islands. Recent studies in
neighboring Calayan group led to the discovery of new species and records. Subsequent surveys conducted on four major islands of
Batanes group in 2006 and 2007 by U.P. Los Baños similarly observed possible new taxa and records. Five reptiles, 10 birds and two
mammals recorded are regionally restricted, echoing the significance of Batanes as a high priority for biodiversity conservation. Seven
threatened and near-threatened species are known from Batanes including Platalea minor, Egretta eulophotes, Treron formosae, Otus
elegans, Terpsiphone atrocaudata, Pteropus dasymallus and Trimeresurus mcgregori. Both regional endemics and threatened wildlife
represent key species for conservation and serve as principal bio-indicators for management. Therefore, it is crucial that protection be
centered on habitats inhabited by key species. Coastal areas and lowland forests surveyed were identified as critical habitats in Itbayat
(Mt. Karoboban; Mt. Riposed; Mahayid cliffs), Batan (Mt. Iraya; Mt. Mahtarem); Sabtang (Malakdang; Vichinyi; Savidug-Chavayan;
Nakanmuan) and Ivojos islands. Most sites represent remnant patches of old growth and secondary evergreen forests that harbor
equally important endemic flora, but were in various degrees of encroachment. Some 30 resident species were consistently recorded
across four islands forming its core fauna, which includes recent colonists and autochthonous island taxa. Several were analogous
with Babuyan and Lanyu, showing geographical affinities and faunal similarities with Batanes. Moderate diversity exhibited by these
isolated islands apparently relate to limited mobility and niche availability afforded to insular wildlife. Current results enriched the
baseline information on insular vertebrate fauna of Batan, Itbayat, Sabtang and Ivojos islands, vital to community-based management
and local conservation education. Although Batanes’ fauna was not as diverse as most Philippine islands, its inimitable wildlife
represent an important contribution to the country’s natural heritage, and palpable link to north Asia.
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Introduction
Batanes (located 20o 30’ N; 121o 50’ E) is the most remote
province in the Philippines, composed of a cluster of 10
isolated islands between the South China Sea and Pacific
Ocean, covering a total of 23,347 hectares. The three
largest islands of of Itbayat (9,000 ha), Batan (7,000 ha)
and Sabtang (1,600 ha) harbors all five municipalities,
fringed with smaller uninhabited islands such as Ivuhos,
Diadekey and Dinem. The northernmost island of Y’Ami
borders Lanyu (Botel Tobago) Island off Taiwan, thus
sharing Palearctic elements from north Asia, some of
which extend to the Babuyan islands. Despite its isolation,
Batanes still shares distinctively Philippine endemics with
Wallacean Luzon Island. This isolation produced several
endemic reptiles, birds and mammals allied to species
from subtropical Taiwan-Ryukyus or tropical Philippines.
This complementary mix of wildlife regarded Batanes as a
distinct transitional biogeographic region (parallel with
Babuyan Islands).
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Due to its unique geology, endemic fauna & flora, and
indigenous Ivatan culture, the entire province was
designated as a protected landscape & seascape and
UNESCO heritage site. Past biological expeditions were
mostly concentrated around Mt. Iraya in Batan Island that
revealed several endemic taxa, similarly shared with
Sabtang and Ivuhos. Despite being a priority protected
area, little is still known about the wildlife of other islands,
particularly
on
smaller
uninhabited
islands.
Recent
extensive studies in neighboring Calayan group led to the
discovery of new species, new island records and even
new country records. In retrospect, an extensive survey of
terrestrial fauna in four major islands in the Batanes group
is essential to better assess the status of biological
diversity in this unique biogeographical region and priority
protected area.
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Mt. Karoboan, Itbayat
Mt. Iraya, Batan
Vichinyi, Sabtang
Ivuhos Island
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Methods
Extensive surveys were conducted on four major islands of
the Batanes group in April-May 2006 and May-June 2007
by a team of field biologists and students from U.P. Los
Baños. Standard field methods for assessment (transect
counts, trapping arrays and microhabitat sampling) of
amphibians, reptiles, birds and mammals were deployed
on lowland forest sites in Itbayat (Mt. Karoboban), Batan
(Mt.
Iraya);
Sabtang
(Vichinyi)
and
Ivojos
islands.
Subsequent surveys were also done on selected coastal
areas and lowland forests in Itbayat (Mt. Riposed; Mahayid
cliffs), Batan (Mt. Mahtarem) and Sabtang (Malakdang;
Savidug-Chavayan; Nakanmuan). Most sites represent
remnant patches of old growth and secondary evergreen
forests that harbor equally important endemic flora, but
most sites were in various degrees of human disturbance
and agricultural encroachment. Clearance of inherently
limited natural vegetation for subsistence farming and
expanding cattle ranches were noted during the survey.
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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The project was able to provide invaluable field support to
three undergraduate and graduate students. These
included the following wildlife biology and zoology students
from the University of the Philippines Los Baños: Kathy
Lene S. Cielo, conducted a comparative survey of bat
diversity the Batanes Islands (subsequently won 3rd place
for the BPI Conservation Award 2008); Xy-za Chloe B.
Reserva, conducted a survey of forest birds of the Batanes
Islands; and A.V. Lacaste conducted a comparative
Herpetofaunal survey in the Batanes Islands. The survey
was also participated by field biologists from other FFI
partner institutions, including ISLA Foundation (with
Carmela
Española)
and
Polillo
Islands
Biodiversity
Conservation Foundation (with Enteng Yngente). Nearly all
the live captures were release after measurements where
taken, with only a few selected herpetological vouchers
were collected thru an approved gratuitous permit from the
DENR Region 2 and BPLS PAMB.
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Results and Discussion
The field team observed over 20 species of reptiles, more
than 60 species of birds and some five species of
mammals, including several possible new taxa (i.e.,
Eutropsis sp. and Lepidodactylus sp.) and new islandrecords (i.e., Gekko kikuchi, Lycodon bibonius, Pandion
haliaeetus,
Centropus
australis).
Five
bengalensis
reptiles
(i.e.,
and
Gekko
Miniopterus
porosus;
Lepidodactylus balioburius; Draco jareckii; Lycodon alcalai
and Trimeresurus mcgregori), 10 birds (i.e., Rallina
eurizonoides alvarezi; Treron formosae filipina, Ptilinopus
leclancheri
longialis;
Macropygia
tenuirostris
septentrionalis; Centropus viridis carpenteri; Otus elegans
calayensis, Apus pacificus kanoi; Hypsipetes amaurotis
batanensis; Terpsiphone atrocaudata periophthalmica and
Zosterops meyeni batanis); and two mammals (i.e.,
Crocidura attenuata and Pteropus dasymallus) recorded
are regionally restricted to the Batanes-Babuyan islands.
Draco jareckii female
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Presence of regional endemics echoes the significance of
Batanes as a “very high” priority for biodiversity conservation
and a protected landscape. Seven threatened and nearthreatened species are known from Batanes including
Platalea minor, Egretta eulophotes, Treron formosae, Otus
elegans, Terpsiphone atrocaudata, Pteropus dasymallus and
Trimeresurus mcgregori. Current results enriched the
baseline information on insular vertebrate fauna of Batan,
Itbayat, Sabtang and Ivojos islands, vital to communitybased management and local conservation education.
Comparison of faunal composition between the four islandsites indicate 50-60% similarity, with differences attributed to
variable occurrence of migratory birds, waders and islandendemic herpetofauna. Notable species shared with Taiwan
and
Ryukyu
Islands
are
Otus
elegans,
Microscelis
amaurotis, Terpsiphone atrocaudata, Pteropus dasymallus
and Crocidura attenuata.
Otus elegans calayensis
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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The apparent scarcity of indigenous frogs and non-volant
mammals on Itbayat and Ivuhos islands was reflective of
the depauperate amphibian and mammalian fauna of the
Batanes
group.
Some
30
resident
species
were
consistently recorded across the four islands forming its
core
fauna,
which
includes
recent
colonists
and
autochthonous island taxa. Several were analogous with
Babuyan
and
Lanyu
islands,
showing
geographical
affinities and faunal similarities with Batanes, harboring
both typical Palearctic and Wallacean elements. Most
important were several new island records added to the
Batanes group, particularly for the poorly studied Ivojos,
Sabtang and Itbayat islands. These include records for
Eutropsis cumingi, E. bontocensis, Lycodon bibonius,
Sphenomorphus
abdictus,
Gonyosoma
oxycephalum,
Gekko cf. kikuchi and Miniopterus australis, . There are
also unknown species of Lepidodactylus and Rhinolophus.
Pteropus dasymallus
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Trimeresurus mcgregori
Draco jareckii male
Lepidodactylus balioburius
Lycodon alcalai
Gekko porosus
Sphenomorphus abdictus
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Zosterops meyeni
Terpsiphone atrocaudata male
Microscelis amaurotis
Halcyon coromanda
Macropygia tenuirostris
Ptilinopus leclancheri male
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Rhinolophus virgo
Rhinolophus sp.
Cynopterus brachyotis
Pteropus dasymallus
Miniopterus australis
Crocidura attenuata
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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New Island Records for the Batanes Group
Eutropsis cumingi
Lepidodactylus sp.
Gekko kikuchi
Lycodon bibonius
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Eutropsis bontocensis
Sphenomorphus sp.
Cuculus horsfieldi
Centropus bengalensis
Gonyosoma oxycephalum
Ninox scutulata
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Conclusion and Recommendations
Batanes Province harbors a moderately rich terrestrial
fauna due to its limited area and remote location, nearly
equidistant to both Palearctic Taiwan and Wallacean
Luzon. Due to its unique geology, endemic fauna & flora,
and
indigenous
Ivatan
culture,
the
province
was
designated as a protected landscape & seascape, world
heritage site, and a distinct biogeographic region. Past
biological expeditions were concentrated around Mt. Iraya,
Batan Island that revealed several endemic taxa, but little
is known about the wildlife of other islands. Surveys
conducted on four major islands of Batanes in 2006 and
2007 by U.P. Los Baños recorded several possible new
taxa and new island records. At least five reptiles, 10 birds,
and two mammals recorded are regionally restricted, and
several threatened species are known from Batanes.
Trimeresurus mcgregori and survey team at Mt Iraya, Batan
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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These wildlife represent key species for conservation and
serve as principal bio-indicators. It is crucial that protection
be centered on habitats inhabited by key species, including
coastal areas and lowland forests surveyed in Itbayat,
Batan, Sabtang and Ivuhos islands. Most sites represent
remnant patches of old growth and secondary evergreen
forests in various degrees of encroachment. Species
consistently recorded across islands form the core fauna,
of which several were analogous with Babuyan and Lanyu
islands. Moderate diversity exhibited by these isolated
islands apparently relate to limited mobility and niche
availability afforded to insular wildlife. Current results
enriched the baseline information on vertebrate fauna of
Batanes, vital to community-based management and local
conservation education.
Mahayid Caves, Itbayat and Diadekey Island, off Ivuhos
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Both regional endemics and threatened wildlife represent
key species for conservation and serve as principal bioindicators for monitoring and management. Therefore, it is
crucial that protection be centered on habitats inhabited by
these key species. Coastal areas and lowland forests
surveyed were identified as critical habitats in Itbayat (Mt.
Karoboban; Mt. Riposed; Mahayid cliffs), Batan (Mt. Iraya;
Mt. Mahtarem); Sabtang (Malakdang; Vichinyi; SavidugChavayan; Nakanmuan) and Ivojos islands. Moderate
diversity exhibited by the isolated islands of Batanes,
Babuyan and Lanyu, apparently relate to limited mobility
and niche availability afforded to insular wildlife, and
constraints faced by northern and southern colonists.
Mt. Iraya peak, Batan and Nakanmuan, Sabtang
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Although Batanes’ fauna was not as diverse as most
Philippine islands, its inimitable wildlife represent an
important contribution to the country’s natural heritage, and
palpable link to north Asia. Due to unavoidable logistical
problems and limitations, other smaller uninhabited islands
in the Batanes group were not visited, and therefore pose
potential study sites. Further surveys are recommended for
the smaller islands of Diadekey, Dinem, Siayan, Diturem,
Mavudis and Y’Ami. Results of this current survey
hopefully would support establishment of key priority areas
or critical habitats within the protected area, and sustain
future activities focused on local conservation education.
Laticauda colubrina male
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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Acknowledgements
The Batanes Island Biodiversity Survey was generously supported by a grant from the Oklahoma City Zoo, Association of American
Zoos & Aquaria, through Fauna & Flora International – Philippines Biodiversity Conservation Programme, in particular Brian Aucone
and William Oliver, respectively. The authors are grateful for the participation of Kathy Lene Cielo, Xy-za Chloe Reserva, Vicente
Yngente, Mark Vincent Yngente, Jimboy Zafe, Christmas de Guzman, Carmela Española, Pedro Abanador, Enrique de Guzman,
Samuel Castillo, Henry Esperanza, Fausto Balanoba, Marcos Nobleza, Pol Villegas, Armand Gallardo and Fred Intervalo. The
authors acknowledge the support of the following: Basco MENRO Francis Domingo, BPLS PASu George Reyes, Sabtang Mayor
Juan Cabellero, Itbayat Mayor Reuel Ibañes, Governor Vicente Gato, Vice-Gov. Constante Castillejos, DepEd Sup. Emmelinta
Belarmino, DepEd Batanes, Brgy Capt Gato, Baby Baroña, Cantor family, Gerlad Fajardo, Ereful family, Asa family, Abanador family,
Cariaso family, Alavado family, Chemtrad, Asian Spirit Basco, Ivatan Lodge Inn, Click Internet Basco, PENRO Batanes, PAWB Dir.
Mundita Lim, DENR Region 2, Animal Biology Division, Institute of Biological Sciences & Museum of Natural History, University of
the Philippines Los Baños, PIBCFI (PESP-Chester Zoo), Philippine Society for Study of Nature, Babuyan Islands Expedition 2004
and people of Batanes Province.
Final Report on the Terrestrial Vertebrate Fauna Survey of the Batanes Islands, Northern Philippines
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